Drawing-instrument



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F. W. ST ARR.- DRAWING INSTRUMENT.

1 i No. 533,095, Patented Jan. 29. 1895. x

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Q m/cuedoeo' I 8145555555 (No Model.) 2 Sheets-Sheet 2.. I. W. STARR. DRAWING INSTRUMENT.

No. 533,095. Patentd Jan. 29,1895;

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UNITED STATES FERDINAND W. STARR, OF SPRINGFIELD, OHIO. I

DRAWING-INSTRUMENT.

$PECIFIOATION forming part of Letters Patent No. 533,095, dated January 29, 1 895. Application filed December 23, 1893. Serial No.49fl,531. (No modell) To all whom it may concern.-

Be it known that I, FERDINAND W. STARR, a citizen of the United States, residing at Springfield, in the county of Clark and State of Ohio, have invented certain new and useful Improvements in Drawing-Instruments; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in drawing instruments, the several features of which will be fully hereinafter described and claimed.

The object of my invention is the construction of an instrument adapted to drawing a great variety of forms, as parallel lines, angular, circular, radial, elliptical, square, &c.

The object is accomplished by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a plan of the instrument omit ting the finger bar. Fig. 2 is a front elevation of the same with the omitted finger bar shown. Fig. 3 is a detailed view of the axes or shafts at a right angle to these parts as shown in Fig. 2. Fig. 4: is an enlarged view of the under axis with the parallel integral guiding bars. Fig. 5 isfa side view of a modified form of the pencil holder. Fig. 6 is a side elevation of the instrument with the near leg cut away and also a portion of the finger bar.

Like letters and numerals designate like parts throughout the several views.

The metallic frame A is mounted on the three legs n, two in front and one on the rear extension. It has the groove 1 in its upper surface. This groove in form represents a line made by lateral movements of the slotted bar H pivotally held by the stud 3, as the inner end is moved at a right angle to the longitudinal line of the instrument, and although curved is not the arc of a circle. At

the rear end, it has a threaded orifice to receive said stud, and has a square orifice extending through its whole length, corresponding to its longitudinal center and in which is held the sliding-bar D. This sliding-bar moves freely within the orifice of the frame, and inthe front end of which is a bearing for the axis L of the parallel bars E and F, and within which it freely rotates. These parallel guide bars have their centers, radiating from the axis of their shaft, and the position of 'said'shaft must bein line with the vertical longitudinal center of said slidingbar. These guide-bars are not only parallel, but must be radially exactlyin line. The indicator 0 is fixedly attached to the under surface of said sliding-bar, or its bearing plate, and the point of which must be in exact line with the vertical longitudinal center of said s1iding-bar, and the axial center of said guide-bars. To the top of the guide-bar F is attached the circular ring B, on which is marked a graduated scale, which may note three hundred and sixty degrees, or any other suitable division. The two guide-bars have their fiangesin reverse order. The lower is embraced by the grooved head of the pencil holder G; and the other by the grooves in the bottom of shaft I, as shown at Fig. 3.

The guide-bar H embraces the upper shaft I by a central orifice in its inner end. It is slotted at its rear end to embrace the stud 3, and has the pin 2, attached by a screw, at the left of its center- The shaft embraced by the inner end of this guide-bar remains directly over the center of the lower shaft, except when it is desirable to form an ellipsis, when the shaft I is carried along the guidebar E, and the pin 2 is screwed down and made to enter the groove 1 of the frame; and in this position the pencil will describe an ellipsis, the only fixed points being the stud 3, the sliding bar moving with the rotation. The dotted lines showthe position of this guidebar H in moving the same to form an ellipsis.

When it is desirable only to make radial, lon-' gitudinal or transverse lines, the screw m is used to bind' the lower shaft, to prevent its rotating. Over the end of guide-bar H is the spiral spring 8, and above is the finger arm K secured to the shaft I by the nut J.

To operate the pencil grasp the knob on arm K and turn the parts as desired. By pressing down, the pencil rests on the paper, and releasing the pressure the spring raises it, and in this manner dottedlines are readily produced. In the drawings, Fig. 2, it is shown depressed as in use, when the pencil is in contact with the paper on which the drawing is to be made.

The pencil holder G is adapted to slide on the guide-bar. It is hollow to receive the spiral spring 4 and the body of the pencil 5. Said spring presses against the head of the pencil, and causes the point to bear against the paper with a uniform pressure.

At Fig. 5,is shown a modified form of holder G. The metallic plate 6 is attached to the head, and is provided with an orifice at the bottom to hold the lower end of the pencil. To add friction to the pencil holder, a springplate may be used between the guide-bar and its head, and a screw may be used to fasten the same rigidly when necessary. For all transverse and radial movements, the line or angle is determined by the relation of the indicator to the graduated scale, and then the pencil holder is made to traverse the guidebar. In circular, elliptic or other curved movements, the pencil holder remains in a fixed relation to the guide-bar. In making longitudinal marks the pencil holder is slipped to the proper point, or the graduated scale is turned until the point is reached. Then the sliding bar D is moved. This bar having a reciprocating movement, and the principal operating parts being supported thereon,the same may be carried to any center or point from which it may be desirable to work.

At 7" Fig. 1 is a block notched and slipped onto the edge of the graduated scale, which is used as a stop. This or other form of stop may be used; and the object of which is to arrest the scale against the indicator arm, and produce a definite radial movement by the position of the stop on said scale.

The movements possible to the instrument are almost infinite, and only the operations most readily discerned have been described. By using a cord attached to the frame and wound around the shaft L, or by attaching the same to the pencil holder, and wound on a rod central to the instrument, a variety of spiral forms may be made by said instrument.

The position of the guide barE may be changed by placing the grooved head on the shaft L, and attaching the bar E to the shaft I, and the operation would be substantially the same.

I-Iaving fully described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. The combination of the frame A mounted on legs and having a square orifice throughout its length, the sliding-bar D held in said orifice, the shaft L supported in the end of said bar and the guide arm F integral therewith, the circular graduated scale B, the indicator O fixedly attached to said sliding-bar and the sliding pencil holder, to produce circular, transverse, radial or longitudinal lines, substantially as described.

2. The combination of the frame A having a square orifice throughout its length and the irregular groove 1 in its upper surface, the sliding-bar D held in said orifice, the shaft L with the integral guide-bars E and F, the graduated scale attached to the latter, the sliding shaft I, the bar II pivoted to said shaft, the stud 3 to engage the slot in said bar and pin 2 to traverse said groove of the frame, and the pencil holder rigidly held to its arm, to form an ellipsis, substantially as described.

3. The combination of the sliding-bar D, the shaft L with its integral guide arms, the sliding shaft I, the arm H, the spiral spring 5, to elevate the several parts, the operating and depressing arm K and the pencil-holder, to produce continuous or broken lines, substantially as described.

4. The frame mounted on legs with a 1ongitudinal orifice and the groove or guide-way in its upper surface,in combination with the reciprocating bar having three points of connection in a longitudinal line, viz, the fixed pivot at the rear of the frame, the traversing pin for said guide-way and the axial center, the guide-arm provided with an axial bearing on its inner end and a longitudinal slot in its outer end, the principal shaft provided with parallel guides, the sliding shaft mounted on the upper guide of said principal shaft, and with marking appendages for drawing lines, substantially as described.

In testimony that I claim the foregoing as my own I affix my signature in presence of two witnesses.

FERDINAND \V. STARR.

Witnesses:

B. PICKERING, MIoI-IAEL CAHILL. 

